Field
Embodiments related to an audio speaker having a voicecoil running along a dielectric surface of a diaphragm, and a magnetic array configured to direct a magnetic field toward the voicecoil to drive the diaphragm and generate sound, are disclosed. More particularly, an embodiment related to a voicecoil having a conductive winding running along a path on the dielectric surface, centered over and following a middle magnetized portion of a Halbach array, is disclosed.
Background Information
An audio speaker driver converts an electrical audio input signal into an emitted sound. FIG. 1 shows a sectional view of a typical audio speaker. An audio speaker 100 may include a housing 102 surrounding a diaphragm 104 and a motor assembly 108. More particularly, diaphragm may be a thin-walled cone or dome that is connected to housing by a speaker surround that allows diaphragm to move axially with pistonic motion, i.e., forward and backward. Furthermore, diaphragm may be connected with a motor assembly via a voice coil former 112, e.g., a cylinder extending axially rearward from diaphragm. The motor assembly generally includes a voicecoil 110 wound in a helix around the neck portion in an axial direction away from the diaphragm, a magnet 114, and a magnetic return structure to sandwich the magnet between a top plate 116 and a yoke 118. In particular, the magnet may be a permanent magnet that produces a magnetic field, and the top plate and yoke may be shaped to direct the magnetic field across a gap between top plate and yoke. Voicecoil is typically located within the gap behind the diaphragm such that the magnetic field is directed perpendicular to the cylindrical surface of the voicecoil. When the voicecoil is energized by an electrical audio input signal, a mechanical force is generated to cause voicecoil to move diaphragm back and forth to generate sound.